Figure 6.

Immunolocalization of stem SbSUTs with PEP2 antiserum-symplasmic phloem unloading pathway in the mature zone of fully elongated Internode 4. A, Preimmune with secondary antibody control. B, Vascular bundle with the phloem outlined by broken white line. C, Higher magnification of phloem shown in B; inset shows enlarged UV autofluorescent image of C. Immunolabeling of SE plasma membranes in B and C (darts). Nonspecific labeling of metaxylem element walls in B (arrows). Sections were viewed under the fluorescein isothiocyanate filter (excitation, 450 to 490 nm; emission, >515 nm) and the UV filter (excitation, 365 nm; emission, >420 nm). MX, Metaxylem element; P, phloem. Bars = 20 µm, inset bar = 10 µm.